More than 20 million people in the United States use electronic cigarettes or e-cigs as an alternative to tobacco smoking. While many users believe "vaping" is a healthier alternative to regular cigarettes, recent research into the health effects of e-cigs could put a damper on that belief. There's particular concern among dentists that this popular habit could harm users' dental health.

E-cigs are made with a chamber that holds the liquid vaping solution and a heating mechanism to heat the liquid and vaporize it. Users inhale the vapor, which contains nicotine and flavorings, as they would a traditional cigarette.

The nicotine alone can be problematic for dental health as we'll see in a moment. But the vapor also contains aerosols that some research indicates could damage the inner skin linings of the mouth in a similar fashion to the smoke of traditional cigarettes. One study by researchers with the Université Laval in Quebec, Canada found evidence that e-cig vapor increased the death rate of mouth cells, and led to greater cell irregularities over time.

According to other studies, there's evidence that e-cig vapor may disrupt the balance of the oral microbiome, the communities of both beneficial and harmful bacteria that normally live in the mouth. The imbalance in favor of more harmful bacteria could increase the risk for dental disease, particularly periodontal (gum) disease.

Finally, nicotine from e-cigs seemed to create similar conditions in the mouth as it does with tobacco. Nicotine in any form can constrict blood vessels and reduce the body's ability to fight infection and to heal. Research indicates both forms of nicotine increase the risk for dental disease and make treatment more difficult.

These findings only identify conditions created by e-cigs that could be problematic for future dental health. Although we don't fully understand the long-term health effects of this new habit, based on the evidence so far the mouth may not fare so well. It's looking like e-cigs may be no safer for your teeth and gums than the cigarettes they replace.